Turbochargers are forced-induction devices that are utilized to increase the pressure of the intake air provided to an engine. A compressor wheel is driven, for example by an electric motor, exhaust gas from the engine, or both, which pressurizes intake air for supply to the engine. By pressurizing the intake air, the engine may have increased power output compared to an otherwise comparable naturally aspirated engine.
The compressor wheel is rotated within a compressor housing to draw ambient air in and expel compressed air out. The compressor housing generally includes a volute that functions as an outlet, an inlet extending axially from the volute, and a wheel cavity surrounded by the volute and in communication between the inlet and the volute. As the compressor wheel is rotated within the cavity, ambient air is drawn in axially through the inlet at an inducer end of the compressor wheel and expelled out radially through the volute at an exducer end of the compressor wheel.
Compressor housings typically have a unitary construction in which a single component forms the volute and inlet. The complex shape of the volute usually requires that the compressor housing be fabricated using a sand casting technique and can require secondary machining (e.g., machining after the casting is complete), for example, to finish surfaces and form different features. For example, a surface of an interior portion of the volute may be machined after the casting process in order to remove burs and/or other imperfections. Further, residue, such as sand particles, may accumulate on the compressor housing during the casting process. Removal of the residue from, for example, cavities of the compressor housing, may be difficult and time consuming. Additionally, sand casting is a relatively slow process that prohibits the use of a reusable mold, which may increase the cost of the sand casting process and increase a potential for error during the sand casting process.